Printed products are often supplied in the form of scale flows, that is in such a way as to partly overlap one another, from processing stations, for example from rotary systems. If such printed products are not immediately continuously further processed, it is appropriate to intermediately store them in such a way that the scale flow order can be retained. For this purpose it is appropriate to intermediately store in rolls, which represent a limited scale flow wound onto a winding core with the aid of a winding band or tape and said scale flow can again be supplied to the processing operation by simply unwinding. Winding stations for winding on and off printed products in scale formation are known, for example from European Pat. No. 447903 corresponding to U.S. Pat. No. 5,158,242 or from European Pat. No. 477498 corresponding to U.S. Pat. No. 5,176,333.
Using the same or similar winding stations and winding cores it is obviously not only possible to wind on and off printed products, but in general terms flat objects which can be bent without damage about a corresponding radius.
The aforementioned winding stations are operated together with substantially hollow cylindrical winding cores, onto which the winding tape is fixed at its one end. Such winding cores are for example, described in European Pat. No. 236561 corresponding to U.S. Pat. No. 4,832,273. The winding tape is wound onto the empty roll and is unwound prior to the winding on of the printed products. Both the winding cores and the rolls are gripped in the cylinder space or cavity of the core for bringing to winding stations, for removing from winding stations and also for manipulation during storage and storage removal. Therefore within this space are also fitted retaining means, for example in the form of a projection running round the inner circumference. In order to make it unnecessary to take note of the orientation of the core during manipulation, it is appropriate to position the retaining means in such a way that the core has a plane of symmetry perpendicular to its axis.
The rolls can be stored in superimposed manner. However, this means that in the axial direction the core must have the same or a smaller extension length than the wound on printed products, because only in this way are stable roll stacks obtained. In order that the same cores can be used for rolls of printed products of different widths, it is advantageous to dimension them in such a way that their axial extension that is, their axial length is at the most the same as the identical extension of the narrowest of the products to be wound. However, as a result in rolls of wider products the outer areas of the products are not supported by the winding core, which can lead to undesired deformations, particularly in the case of sensitive products and during prolonged storage. In addition, said outer areas can, during manipulation, which generally involves gripping in the core cavity, be damaged, which is also not desired.
European patent application 453765 corresponding to U.S. Pat. No. 5,354,008 of thee same applicant describes winding cores, whose axially outer areas are constructed in the form of spaced projections. Such cores or corresponding rolls of printed products, which are narrower than the core, are stacked in such a way that the projections of one core engage in the gaps between the projections of the core below it. This leads to very stable stacks and the printed products are also supported by the core in their outermost areas and this applies to different printed product widths within certain limits. However, stacking must be performed very carefully, because the projections must be very accurately aligned with the spaces and even minor divergences from a precisely coaxial position of the rolls to be stacked on one another can lead to damage to the product edges in the spaces between the projections.